单向陶瓷基复合材料阻尼计算方法

Analytical method for estimating the damping in unidirectional ceramic matrix composites

根据陶瓷基复合材料界面脱黏区及黏结区纤维和基体的应力分布,分析了拉伸和卸载时纤维相对基体的滑移机制,发展了单向陶瓷基复合材料阻尼的计算方法,并进行了数值分析.结果表明:①陶瓷基复合材料本身固有黏弹性阻尼很小,材料发生基体开裂后,界面滑移而引起的摩擦耗散成为材料主要的阻尼机制;②减小界面剪应力或减小纤维体积含量可以改善材料的阻尼性能;③材料阻尼随裂纹间距的增大而减小.

Based on the stress distribution in the bonded and de-bonded region of ceramic matrix composite（CMC） with matrix cracks,the sliding mechanism of CMC was investigated,and the analytical method for estimating damping capacity in unidirectional CMC was derived.Numerical examples show that：（1） CMCs＇ inherent damping capacity is very small.The damping of CMC is mostly caused by the frictional energy dissipation along the damaged fiber-matrix interfaces.（2） The damping capacity of CMC will increase with the decreasing interfacial shear stress and the volume fraction of fibers.（3） When the matrix crack spacing increases,the damping coefficient of CMC is decreased.